1. Field of the Invention
The key selector apparatus provides means for selecting out of the twelve tones of an octave those needed for any key of the diatonic scale or for any key of the hexachord scale.
2. Description of the Prior Art
Traditionally, keyboard instruments play the diatonic scale on the front digitals of the keyboard and intermediate pitches on the back digitals. The major mode of the diatonic scale starts with a C tone, played on a C front digital. The succeeding D,E,F,G,A,B tones are played on the succeeding D,E,F,G,A,B front digitals. In the traditional system of music notation, the C,D,E,F,G,A,B tones are represented by symbols on the lines and spaces of a five line staff. An intermediate tone is represented by one of the above notes of the diatonic scale, together with a .music-sharp. or a .music-flat. symbol serving as a tone correction to that diatonic tone. Thus a tone intermediate to the C and D tone is represented by C.music-sharp. or D.music-flat., and it is played by a back digital position between the C and D front digitals.
For a musical composition to be played on the front digitals of a conventional organ, it must be written in the key of C. Such a restriction severely limits the choice of a composer, for he probably wants to base his composition on the major mode of the diatonic scale starting on a tone above or below the C tone be to specify a movable C major scale in which the pitches played by all digitals are bodily moved a specified distance upward or downward--say four semitones upward. This method has not been available to past composers and their publishers, because most musical instruments have not possessed the pitch changing device which is required for this method. Consequently, composers have resorted to a less satisfactory second method for specifying the absolute pitch of their diatonic scale; they start the major mode of the diatonic scale on one of the other front digitals of the keyboard. This method requires that one or more of the back digitals of the keyboard be included in the diatonic scale.
For a given pitch of the major mode of the diatonic scale, the same back digitals must always be included. Consequently the composer finds it convenient to include these particular sharps or flats in a key signature that is placed at the front of each line of written music. The composer can start the major mode of his diatonic scale on any one of the seven front digitals in an octave span, and he can use either all flats or all sharps with each digital. Thus he uses fourteen different key signatures in addition to the key of C which requires neither sharps nor flats.
The inexperienced player has difficulty remembering and playing all the sharps or flats called for in the key signatures. To alleviate this difficulty, a keyboard instrument can be provided with a device to physically actuate the digital corrections included in the key signature. Such a device, which I call a key selector, can be set to the key signature by the musician; after that he can play the diatonic scale on the front digitals.
Cornelius, in U.S. Pat. No. 2,484,930 has described such a key selector switch interposed between the tone generator circuits and the digital switches. When set for a key signature with two flats, for example, it connects the B and E digital switches to the B.music-flat. and E.music-flat. tone generator circuits. The keyboard contains two extra upper digitals labeled B.music-sharp. and E.music-sharp., so that when the written music calls for B or E natural, these tones can be obtained by playing the B.music-sharp. or E.music-sharp. upper digital.
While the composer has made known the preferred absolute pitch for his musical composition by the location of his notes on the staff and by his key signature, the keyboard player may wish to use a different absolute pitch. He is likely to have some valid need, such as to accompany a singer or another musical instrument with a limited range of absolute pitch. A change of pitch can be accomplished without changing the key digital if a pitch changer is available which raises the pitch coupled to each digital by a fixed amount, such as four semitones. Many inventors have described pitch changers to be used by the keyboard player for this purpose.
The most satisfactory pitch changing switch is one which can be set to a standard position in which middle A has a fundamental frequency of 440 Hz. The switch preferably has at least eleven other discrete positions in which each pitch is changed from its standard value by an integral number of semitones.
Bode, in U.S. Pat. No. 3,023,659, has described a pitch changing system having a sequence of twenty-three primary tone generators and a twelve pole selection switch which selects a sub-sequence of twelve tone generators. These supply the top octave of tone generators for an electronic organ; lower octaves are derived from the top octave by means of twleve chains of bistable frequency dividers.
The switches that I call pitch changers do not change the musical interval between tones played by adjacent digitals, which I call the interdigital intervals. This characteristic of interdigital invariance distinguishes pitch changing switches from other members of the class of tone transposition switches. So far as I am aware, publically described tone transposition switches all belong to this subclass of interdigital invariant switches, except for the previously mentioned Cornelius key selector and except for my scale selecting switch, disclosed in U.S. Pat. No. 3,141,371. I found that my scale changing switch could not use the Bode trick of pre-divider switching; it belongs to a subclass that requires post-divider switching.
Restriction to the subclass of interdigital invariant switches allows special techniques which are not available to the general class of tone transposition switches. Examples are pitch changers disclosed in U.S. Pat. Nos. 3,836,909 - COCKERELL and 3,610,800 - DEUTSCH. Another example is U.S. Pat. No. 3,030,848 - WICK, in which a linear array of contacts permanently coupled to the digitals slides along a linear array of contacts permanently coupled to the tone actuators.
Pitch changers and Cornelius-type key selectors, which perform quite different functions, are both useful additions to a musical instrument.
I have disclosed an organ with a hexachord keyboard using hexachord notation in my copending patent application number 507,118 filed Sept. 18, 1975. Notation for six-tone scales appears to have important advantages over diatonic notation for players of all musical instruments and especially for singers.
In hexatonic notation, three of the tones are always assigned to lines of the staff; the other three tones are always assigned to spaces. Moreover, positioning of the tones in the upper five-line staff is the same as the positioning in the lower five-line staff.
Recent interest in hexatonic scales has centered on the whole tone scale. This has equal musical intervals of two semitones between each pair of consecutive tones in the scale. The whole tone keyboard, constructed as shown in FIG. 1, has the enormous advantage that any chord can be played at all absolute pitches with only two different fingerings. For teaching music to beginners, however, the whole tone scale has the serious disadvantage that it does not contain the musical intervals of fourths and fifths, which are basic to the early development of music appreciation. And since the tones of the whole tone scale are uniformly spaced, there is no natural basis for development of loyalty to a particular home tone. Up to the present time, no attempt to promote the whole tone keyboard has been widely accepted.
Six-tone scales other than the whole tone scale, which I call "irregular" hexatonic scales, must inherently include at least one musical interval of three or more semitones. One such scale is the hexachord, characterized by the intertone intervals 2-2-1-2-2-3 semitones. An organ with a hexachord keyboard is described in my U.S. Pat. No. 3,865,004.
For teaching music to beginners, I prefer the hexachord scale over the whole tone scale. The hexachord scale includes the musical intervals of fourths and fifths, and its "irregularity" serves as a focal point in tonal development. The hexachord scale is familiar to the ear, since it consists of the first six tones of the diatonic scale. The syllables do-ra-mo-fa-so-la denoting these six tones help to fix three of the tones to lines of the staff and the other three tones to the spaces. The seventh tone of the diatonic scale is notated as C.music-flat., and it is played on a back digital.
In my standard hexachord notation, tones corresponding to lines of the staff constitute the C major triad; tones corresponding to the spaces constitute the D minor triad. When several tones are to be sounded simultaneously, a further dichotomy may be effected by positioning the notes of the tonic major triad on one side of the common stem, and the notes of the supertonic minor triad on the other side of the stem, as indicated in FIG. 2. Thus the standard hexachord notation provides a fixed and intimate association between the written representation and the sounds of music.
The standard hexachord notation is especially suitable for singers, who can sing from the written music at any absolute pitch that suits their voices. Grove's Dictionary of Music, 1954, under "Scale" records the truth "Music is an art not of notes but of intervals." In my standard hexachord notation, the notes are not intended to represent fixed absolute pitches, but only intervals with respect to a C-tone of variable absolute pitch. When singers using standard hexachord notation are accompanied by a piano or organ, the accompanist may read from the same music, for it is now simple and economical to provide an electronic piano or organ with a pitch changing switch.
For a simplified system of musical notation to be considered seriously, some hard questions must be asked, including:
1. Can the system be extended for use by players of all kinds of musical instruments, including those without pitch changers?
2. Can musicians trained in the simplified system easily adapt to music written in the system thus extended?
3. Can musicians trained in the simplified system easily play the large body of printed diatonic music which is stocked and distributed by the music publishing industry?
My invention assists in answering these questions.